Transcript Partenaire de L`Ozone - EU-MESH

Ozone's Presentation to EUMesh
Ozone presentation
 French Wireless ISP Founded in 2004...


Goal : allow “Everywhere, EveryTime, Cheap and Effective connectivity” and
build a pervasive network
Wifi was at that time the obvious choice for developing the network (cheap,
widespread, flexible, no licence)
 but Ozone is fundamentaly technology agnostic
 ...and bought in 2007 by Neuf Cegetel





Neuf Cegetel is the French second major Telco and ISP
3000 employees
Counts with 4M DSL clients (retail)
Important market share in Business clients
…To be bought by SFR, second French mobile Operator, within weeks…
Network logic (1)
 Antennas on rooftops to provide a local coverage

We don’t pay for accessing rooftops : we gain access through individuals
“offering” their rooftop in exchange of free access to our services
 They also power the installation (~20 W)

5 Radio cards on each roof :
 3 * 2.4 GHz (=3 * 120 °) for clients connections
 2 * 5 GHz for backhauling functions
 Multiply roofs to offer a full coverage of the city


About 1000 roofs to provide a first mapping of the city (105 km²) / Each roof
covering ~ 200m radius circle
Full coverage provided through additional deployments (Urban furniture,
lamposts…)
 Backhaul roofs with efficient and affordable technology

Provide symmetrical Throughput
 At least 8 Mb/s on each roof

Mainly Wireless Point to Multipoint using 5GHz (802.11a)
 Free licences, good throughput, cheap hardware
 Needs Line Of Sight (LOS) between roof and Concentration sector

…but also ADSL, Fiber, Wimax (when no LOS)
Network logic (2)
 Each roof is connected to a concentration sector

Through a 5GHz link based on 802.11a
 A concentration sector is a sector antenna connecting up to
8 roofs

About 25 Mb/s IP available at each sector antenna to dispatch among roofs
 Concentrations sectors are located on high buildings in
Paris


9 of these building today
Each building connected to the internet through fiber
 Up to 20 concentrations sectors per building

Limited by frequency reusability
 Each roof might connect another roof itself

Handy for sites that don’t have LOS to Concentration points
Clients
 3 plans

18 € for unlimited monthly access
 About 2500 clients each month

7,8 € for a daily pass
 About 1000 clients

1,5 € for a 1 hour pass
 About 6500 clients
 About 10K users more at partners sites
 Deal : indoor coverage and free internet access in exchange of roof access
 Museums
-
Palais de Tokyo
Museum of Modern Art Centre Pompidou
 Hospitals, Firms, associations
Today’s network (01/2008)
250 roofs
Concentration Sector focus
roofs
RSSI :
RSSI > -70 dBm
On both side.
Concentration Sector
Roof with no LOS
DSL as backhaul
 Standard DSL link used

Up to 20 Mb/s DL | 1 Mb/s upload
 Tunnels used to hide the DSL layer


Allows to monitor transparently the roof connected
The user has no knowledge he is using a DSL link
A typical roof (1)
Omni-directionnal
Antenna (5GHz)
Sector Antennas
(2.4 GHz)
Directionnal Antenna
(5GHz)
Outdoor Case
A typical roof (2)
Concentration sectors
Directionnal Antennas
(5GHz)
Sector Antennas
(5 GHz)
Hardware
 Mikrotik Boards

RB532A (discontinued now)





RB600




MIPS architecture
64 MB SDRAM
3 Mini-PCI slots
~50 % CPU load on concentration sector with high throuput (~15-20 Mb/s)
PPC architecture (400 MHz)
64MB SDRAM
4 Mini-PCI
« daughter boards » plugged to main board

To add Mini-PCI slots and reach 5 Wifi cards per roof
 Wifi Cards


Atheros chipsets (AR5213 baseband / AR5112 RoC) 802.11 a/b/g
Tests ongoing on 802.11n

Seems especially interesting for enhancing coverage in Ozone’s case
 Antennas


2.4 GHz sectors (120°)
5 GHz sectors / directionnals / omnidirectionnals
Software
 Mikrotik RouterOS

Handles Point to Multipoint topology nicely
 Important in our Backbone to avoid the « hidden node » problem

No Open source philosophy here
 A problem to integrate innovative solution
 OpenWRT

On roof using DSL as a backhaul link
 OpenVPN not well implemented on RouterOS
At the IP Level
 All the network is routed

OSPF in the backbone


Up to concentration sectors
Then static routing
 BGP peering with Tier 1/2 provider

FreeBSD server running bgpd and ospfd
 QoS introduced

Assuming each roof has 8 Mb/s, traffic prioritization






Snmp, ssh
DNS, small packets (ACK), SIP
Web, mail
Other traffic
P2P
Problem is we don’t know actually what throughput is available at a given time on the
wireless backhaul link
 Authentification

Radius & MySQL databases


FreeRadius used
Proxy services offered to partners (T-Mobile, Neuf Cegetel…)
Operations / Management
 Deployment

Made through Third parties contractors which have limited but necessary
knowledge of the network
 Implies they have a PC while deploying to verify antennas orientation, radio
association, etc…
 Monitoring and maintenance

SNMP Through Open Source softwares
 Nagios for Network surveillance, availability reports, network instant trends
 Cacti for graphing

Own developped tools for mass configuration / maintenance
Services
 Services offered

Standard internet access
 Throughput offered may vary according to the client's connection quality with the
infrastructure and overall load ; goal is to provide 2 Mb/s symetrical

Telephony
 SIP based ; we operate our own SIP proxies and have a PSTN connection through
a business partner
-
SIP Proxies based on Asterisk and SER
 We offer as well SIP transit services to partners (Neuf Cegetel mainly…)
 About to launch

Geo-localisation services
 Through IP based localisation : 200m precise in Ozone’s case
 Through third party software : cf www.loki.com

“Mobility” services
 Integrating various backhaul technology transparently for the users through tunnels
-
OpenVPN based (transparent to user)
Overhead might be a problem (up to 20% up to now)
Deployment relevant to EU-Mesh
 100 lamposts in Paris


To be deployed end of May
Each lampost will be equiped with a 3 radio AP
 1 * 2.4 GHz radio (802.11 b/g(/n)) for clients connectivity
 2 * 5 GHz radio (802.11 a) for backhaul

Lampost might be backhauled by
 5GHz link (Ozone network) ; majority of them
 DSL link (directly or through wireless hop)
 Wimax link

Goal is to provide seamless mobility for clients moving from lamposts to
lamposts
 In some area, we will deploy APs on up to 10 lamposts
 100m distance between each lampost in these areas
 Mobility will be checked with Surf and VoIP
-
Either through tunnels, or WDS
 In the same area, different backhaul solution might be adopted simultaneously
Lampost deployment
 EU-Mesh trials could be done on a portion of this
deployment

Comparison of EU-Mesh and standard 802.11 networks
Ozone
5GHz
PoE
5GHz
PoE
100 m
5GHz
PoE
5GHz
PoE
100 m
5GHz
PoE
PoE
100 m
Network flaws (some of them…)
 Coverage is still low

A way to enhance coverage in a cheap and convenient way would be very
helpfull
 No Mesh in the network

Deployment could be a lot easier
 Mesh network implying zero-configuration during installation would be a great
feature for us

Auto-reconfiguration on failure would be a very interesting feature
 Though our antennas are fixed, we have an Omni-antenna we could benefit from to
enhance resilience in the network
 Other hardware configuration could be studied and deployed to enhance resilience
-
Though major cause for outages in our network is power shortcuts
 « Dumb » network

Poor QoS settings
 Beeing able to locally manage QoS (based on actual Throughput) and have
information on a full path (and not only a node) from a QoS point of view would be
a very appealing feature

No interferences handling
 Neither at 2.4 GHz nor at 5 GHz